This invention relates to a stunt kite which is controlled by two strings.
Many stunt kites are presently available which are controllable by two strings, whereby an operator can pull on one string or the other to cause the kite to perform a variety of maneuvers. Numerous configurations are available including kites which are diamond-shaped and delta-shaped.
Diamond shaped stunt kites fly primarily due to the "sled effect," i.e. the upward forces produced by the impact of the wind on the inclined downwardly-facing windward surface of the sail. These kites often have a cross strut with two halves which are connected to the keel strut by a rigid plastic fitting. The dimensions of the components are usually such that the sail is stretched and taut.
Some stunt kites such as the kite disclosed in the U.S. Pat. No. 4,286,762 have the so-called Rogallo shape in which the leading end of the keel strut is connected to two rearwardly swept wing struts so that, in flight, the sail forms two funnel shaped bodies. Each hemisphere acts as a foil which provides lift as it generates apparent wind speed in addition to the sled effect caused when the wind deflects off the lower surface of the funnel.
Single string stunt kites are also available. These kites, commonly called "fighters," were developed in Asia. They generally have a taut diamond-shaped sail, a longitudinal keel strut which extends from the nose to the tail, and a cross strut which extends from wingtip-to-wingtip. The cross strut normally lies in a plane which is parallel to the plane of the sail, and it is bowed in a direction which sweeps aft. A bridle is connected to an aft point on the keel strut, and to the point where the keel strut and the cross strut interconnect. It has been proposed in the prior art to use a wingtip-to-wingtip bowstring on a fighter kite. To control a fighter kite, the operator lets the control string go slack so that the kite becomes unstable and, when its nose is pointed in the desired direction, the string is pulled taut, so that wind forces push the cross strut into an oblique plane to drive the kite in a noseward direction.
The present invention has resulted from the discovery that, by combining known features of the fighter kites with known features of two string stunt kites, a new kite with characteristics superior to both is produced.
The kite of the present invention has many favorable attributes. It has a high strength-to-weight ratio, which makes it possible to manufacture it of relatively lightweight components. Due to its low mass, the impact of a crash will reduce the damage to the kite and to anything it strikes. The kite performs quite well in winds as low as two or three miles per hour, yet it performs well in higher winds up to 25 or 30 miles per hour. The kite is easily flown by a beginner, yet it is highly maneuverable in the hands of a skilled stunt kite operator. The kite also can be self-launched after a crash.